using ++ in jquery

Just a quick one. I need a simple animation that basically says.

$("#rightArrow").hover(function() { $('.projectImages'开发者_运维问答).css('left', '++27px'); });

I've tested it and it seems that the ++ is the wrong syntax here. Just wondering what it was that was supposed to go in. I've tried += and I've also tried using the animation feature but the closest I've got so far is this

$("#rightArrow").hover(function() {
    $('.projectImages').animate({left: '+=27px'}, 'slow');
});

Which gives some interesting results but not quite what I was looking for.

I'm not sure there's a quick and easy way to do it, due to how Javascript handles strings and integers. Try:

$("#rightArrow").hover(function() {
    newLeft = parseInt($(this).css('left'), 10) + 27;
    $('.projectImages').animate({left: newLeft + 'px'}, 'slow');
});

I managed to create a fiddle with a continuously sliding object by starting/clearing an interval function:

timer=null;

$("#rightArrow").hover(function(e) {
    timer=setInterval( function(){
      var left = $("#x").position().left;
      $("#x").animate({
          left: ""+(left+100)+"px"
      });
    });
    //alert($("#x").position().left);
}, 
function(e){ // exit function
    clearInterval( timer );
}
);

in Javascript if you are using eval() you are probably doing something wrong. Use parseInt() instead.